Learning to read 2,500 pictorial symbols, as Chinese students do in grade school, yields a 5-point advantage on IQ tests, compared with the scores of Westerners whose languages are based on alphabets, according to a new analysis of mental capabilities of Greek and Chinese children. The international team of analysts, led by psychologist Andreas Demetriou of the University of Cyprus in Nicosia, attributes the scoring disparity to a superiority in visual and spatial tasks that comes with learning to read Chinese.

"Our findings support the assumption that reading and writing systems are powerful methods for influencing the development of mental abilities, and perhaps brain growth, in individuals and in cultures," Demetriou says.

First, the team considered a measure of general intelligence derived from IQ scores (SN: 2/8/03, p. 92: Available to subscribers at http://www.sciencenews.org/articles/20030208/bob10.asp). Overall, Greek and Chinese kids exhibited comparable general intelligence despite a slight IQ advantage for the Chinese. This new finding, which appears in the March/April Intelligence, undermines the controversial proposal of an innate intelligence advantage for Asians, as compared with whites. That view is supported by recent reports of slightly larger brain sizes, corrected for body size, among Chinese people.

Demetriou and his colleagues tested 120 Greek and 120 Chinese schoolchildren, ages 8 to 14. The group included an equal number of boys and girls from each country and from each grade. Most of the kids came from middle-class families.

The pattern of findings at different ages indicates that the edge derives almost entirely from the honing of spatial sensibilities in Chinese readers, Demetriou says. Extremely small proportions of both Chinese and Greek 8-year-olds scored high on spatial problems. By age 12, however, 18 percent of Chinese kids ranked as highly efficient visualizers, compared with 6 percent of Greek children. That gap slightly diminished by age 14, with 26 percent of Chinese and 16 percent of Greek youngsters qualifying as particularly good visualizers.

The study shows that "what have previously been argued to be differences based on biological qualities can be explained by differences in experience that often vary with racial or cultural membership," remarks psychologist Marc Lewis of the University of Toronto.

Demetriou acknowledges that his interpretation of the data requires that additional experiments show that Westerners who learn to read only Chinese score higher on spatial tasks than do Chinese who learn to read only an alphabetic language.

The new evidence that the Chinese writing system influences spatial perception "is plausible but far from definitive," says Yale University psychologist Robert J. Sternberg. For instance, he notes, Asians might possess an evolved spatial facility that promoted their adoption of pictorial symbols in writing rather than alphabetic ones.

Canadian psychologist J. Philippe Rushton of the University of Western Ontario in London says that other evidence leans toward a biological basis for the IQ differences. "Something innate" gives the Chinese a mental edge over whites, he says, noting that Chinese kids adopted at birth by U.S. parents also tend to score higher on IQ tests than their white peers do. Rushton champions a controversial evolutionary hierarchy of racial intelligence in which East Asians come out on top.